Balanced slide-valve



(No Model.)

L. P. NORMANDIN.

BALANCED SLIDE VALVE.

Patented Nov. 14, 1882.

F -JZ UNTTTD STATES LEVI P. NORMANDIN, OF JACKSON, MICHIGAN.

BALANCED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent N 0. 267,450, datedNovember 14, 1882- Application filed July 27,1882.

(No model.)

To all whom it may concern:

Be it known that I, LEVI P. NORMANDIN, of Jackson, in the county ofJackson and State of Michigan, have invented new and useful Improvements in Balanced Slide-Valves; and I hereby declare that thefollowing is a full, clear, and exact description thereof, referencebeing had to the accompanying drawings, which form a part of thisspecification.

The nature of this invention relates to eertai'n new and novelimprovements in the construction of slide-valves of that class which areprovided with a fiat face or bearing-surface.

The object of the invention is to constructa slide valve that shall beperfect in its operation, and which shall avoid the necessity ofincasing the valves as they are ordinarily con structed.

The invention consists in the peculiar construction and arrangement ofdevices for retaining the slide-valve in its proper position upon itsseat, and in the peculiar construction, arrangement, and variouscombinations of the parts, all as more fully hereinafter described.

Figure l is a central vertical longitudinal section through thevalve-seat provided with my improved valve. Fig. 2 is a verticalcrosssection on the line 00 or in Fig. 1. Fig. 3 is a side elevation ofthe valve.

1n the accompanying drawings, which form a part of this specification, Arepresents the valve-seat, which is provided with the ports a, whichlead to the cylinder, and with the ex haust b, as in the ordinaryconstruction.

B represents my slide-valve, provided with theports c, which, in theoperation of the valve, coact with the ports a in conducting steam tothe cylinder.

d represents the exhaust space or cellar in the face of the valve, and ethe inlet-port in the side of the valve B, there being such a port 0 ineach side of the valve to receive steam from acrotched steam-supply pipewhere the work to be performed by the engine shall require it. Theseports 6 are elongated in their opening, as shown in Fig. 3, and the endsof the steam-supply pipe are brought in close proximity to the sides ofthe valve,.and are provided with any suitable packing which shallproduce a steam-tight joint at that point, but that will allow of thetravel of the valve.

G represents guide-plates, which are rigidly secured to the valve-seatby proper bolts; or they may be formed as an integral part thereof.These guide-platesembracethe sides ofthe valve, and are for the purposeofholding such valve in its proper position in relation to thevalve-seat, and through these guide-plates are carried the steam-supplypipes in order to give rigidity to the parts, the packing hereinbeforereferred to being in this case upon the inner face of the guide-plates.

From or near each corner of the valve-seat there rise four standards orposts, D; and E is a plate in which are formed suitable holes, whichcome coincident with the posts in such a manner that the plate will slipover the posts or standards, and, besides performing the functionhereinafter described, will serve as a girt or girts to preventthespreading of the posts at their upper ends.

The upper face of the valve is recessed, as shown at h, to receive thelower ends of the truncated or mutilated rollers F, the upper ends ofwhich are received in a similarly-recessed downward projection from thebottom or under side of the plate E, such recess being one of suificientwidth to allow the rollers to freely oscillate.

G represents coil or other suitable springs placed around the upper endsof the posts D, the lower ends of such springs resting upon the top ofthe plate E, while their upper ends find resistance against theplates H,which are held in place by proper nuts, I, upon the ends of thestandards. The action of these springs and their power is exerted uponthe plate S, which compels such plate to force the mutilated rollersdown upon the top of the valve and hold it to its relative position uponthe valveseat. The amount of pressure thus brought to bear upon thevalve should be somewhat greater than that required to blow off steam attheboiler; and it can readily be seen that such pressure can easily beincreased or diminishedby screwing down or easing up the nuts I. Vhile Ihave described and show a pair of these truncated rollers upon each sideof the valve, I do not desire to confine myself I00 to such preciseconstruction and number, as in smaller engines it may be preferable touse but one pair of such rollers and have them bear directly upon thelongitudinal center of the valve.

At each end of the valve, and at a suitable distance therefrom, Isecureto the valve-seat, or the so-called steam-chest seat, a cylinder, J,provided with a piston, K, the stem of each of which projects throughthe head of its respective cylinder, and is received into a properrecess in the under face of the plate E, at or near the outer endsthereof. Each of these cylinders is provided withasupply-pipe, L, bymeans of which steam may be admitted to the cylinders, which will actupon the re' spective pistons and force the plate E upward against theforce of the coil-springs hereinbefore described, thus relieving thepressure of such springs and the connections described upon theslidevalves, and avoiding the danger and liability of the cutting of thefaces of the valve and valve-seat at such times that the supply of steamhas been cut off from the engine and the engine still continues to run.

While I have described the valve as receiving steam from a crotchedsteam-pipe upon each side of the valve, it is obvious that one of theseinlet-pipes may be omitted, and as a Substitute therefor a suitablecovering or cap and packing be employed in the guide-plate to cover upthe opening through the plate and to prevent the flow of steam directlythrough the valve without exerting any force thereon.

I deem the oscillating m utilated rollers F important, as the bearing bythis construction is equally divided between the plate E and the valvesWithout rubbing or wearing either part, and I also attach importance tothe cylinders J in their relation to the valve B, plate E, and springs.

That I claim as my invention is-- 1. In combination with the valve-seatof a steam-engine, the valve B, having recesses h, the plate E, held byspring force in the direction of said valve, and the mutilated rollersF, constructed to give equal bearings upon said valve and plate, as setforth.

2. The guide-plates O, rigidly secured to the seat A, combined with thevalve B, having recesses h, the mutilated roller F, plate E, andsprings, as set forth.

3. In combination with a valve held to its seatby adjustable springforce applied to a plate, auxiliary steamcylinders having independentsteam-inlets, and pistons operating therein to overcome the spring forceand relieve the valve of the pressure of the spring, as specified.

4. The auxiliary cylinders J, having pistons K and steam pipes L,combined with the springs G, plate E, mutilated rolls F, and valve B, asand for the purposes set forth.

LEVI P. NORMA NDIN.

WVitnesses:

H. S. SPRAGUE, E. SoULLY.

